Commands for WREN SSTV Released

WREN - Image credit Stadoko

WREN – Image credit Stadoko

It is believed that the SSTV PocketQube WREN is currently in a mode where it beacons on 437.405 MHz for 1.6 seconds then listens for 6 minutes on that frequency for any commands. If none are received it goes to sleep for 2 minutes before transmitting the beacon again.

The WREN team have released the following information on their Facebook page to enable radio amateurs to activate the WREN SSTV transmitter.


Commands to WREN are sent by toggling the carrier [of a FM transmitter]:
Carrier on/off: 1=long, 0=short, leave a noticeable silence between the bits.

• Activate/HK: 110011
• wait until answer [should be within 2 seconds]
• Camera ON: 11111
• wait until answer
• Snapshot & Thumbnail receive: 110
• decoder should display thumbnail picture 12*14 pixel can repeat this command until something useable appears
• SSTV send: 110100
• martin-1 SSTV picture comes… in 320×240 pixels color

Wren should answer to the commands within two seconds.
Wait always at least two seconds after having received data before sending to WREN

Send the Activate/HK command first, else WREN won´t react to other commands.
When camera is OFF, a snapshot or SSTV command will send WREN into sleep mode. ALWAYS SWITCH CAMERA ON FIRST BEFORE SENDING CAMERA COMMANDS.
WREN´s housekeeping data will show the status of camera power (ON or OFF).

PS: A preliminary commanding software will come soon.
Special wishes for PTT control? VOX, RS232-RTS Pin etc ?

The Telemetry Decoder and an Audio File of the beacon are available at

Hope you can catch WREN and have fun commanding it.

Cheers, Paul

WREN on Facebook

WREN a Ham Radio Slow Scan TV PocketQube Satellite

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